First part of render texture commit

Added NzContext::EnsureContext and NzContext::GetThreadContext
Added NzCube
Added NzRect::GetCenter
Added methods to send vectors to shaders
Added NzRenderer::SetViewport
Fixed NzRect::ExtendTo calculations
Fixed NzImage::Update checks with level > 0
No longer use glTexStorage when creating a texture to prevent a bug
NzBuffer's Lock and Unlock operations renamed to Map and Unmap
NzVector2/3/4 can now cast implicitly to a pointer
Optimized compilation time of String.hpp
Optimized normalisaton of quaternions
Optimized passing uniforms to shaders
Quaternion now automaticaly Normalize h
Removed macro definition of NAZARA_RENDERER_OPENGL from Renderer
Removed implicit cast from NzVector2/3/4 to NzString
Renamed nzBufferLock to nzBufferAccess
Renamed NzRenderTarget::CanActivate to IsValid

include/Nazara/Math/Vector4.inl

@@ -120,9 +120,15 @@ NzString NzVector4<T>::ToString() const
 }
 
 template<typename T>
-NzVector4<T>::operator NzString() const
+NzVector4<T>::operator T*()
 {
-	return ToString();
+	return &x;
+}
+
+template<typename T>
+NzVector4<T>::operator const T*() const
+{
+	return &x;
 }
 
 template<typename T>